Molded commutator-cylinder and method of forming same



w. H.- KEMPTON.

MOLDED COMMUTATOH CYLINDER AND METHOD OF FORMING SAME.

APPLICATON FILED SEPT. 10. 1917.

1,396,349. 1mm Dec. 30, 1915).

WITNESSES I INVENTOR @ofi e m mwmz ire/ m 1 I v BY 7 ATTORNEY UNITE STATES PATENT oFFIon wiLLABn H. xiaiar'ron, or WILKINSBURG, PE msYLvANIA, ASSIGNOR T wEs'rING- HOUSE ELECTRIC & MANUFACTURING COMPANY,.A. CORPORATION. OF .rENNsYL- MOLDED COMMiJTA'l0R-CYLINDER AND METHOD OF FORMING SAME.

4 To dll wkom it, may concern:

Be it known that I, lVnLnano H. KEMP- To a citizen .of the United States, and a resident of \Vilkinsburg, in the county of Allegheny and State of Pennsylvania, haye invented a new and useful Improvement in Molded Commutator-Cylinders and Methlods of Forming Same, of which the followa specification. r y invention relates to commutator cylinders and particularly to commutator cylinders in which the assembled conducting and insulating sections are held in position by molded insulating material.

' Inmy PatentNo. 1,28%,36'2, dated Nov.

' 12, 1918, is shown a con'nnutator cylinder that is formed by assembling alternate. conductingand insulating sections and then roper posi ons.

P balrelite that is applied in a- --.'.applying an insulating material by n'kcans of. a sultable mold to hold them in their The insulating material s preferab plastic eon ition, and it has been found that as the particles of insulating material move over the surfaces of the conducting sections, under the influence of heat and pressure, minute flakesof copper are sometimes removed from the surfaces oi the bars on account of the securing action of the insulating, material. These flakes of copper are liable to cause short circuits betwecn -'adjacent conducting sections.

- By my invention, '1 provide means for protecting the surfaces of the conducting sections against the above described scourin action.

in the single figure of the accompanying drawing, alternate conductin; and insulating sections 1 and 2, respectively, are shown arranged in annular form 'with portions thereof, embedded in molded insulating material 3 that is supported upon a hollow cylindricalsleeve 4 by means of which the.

commutator cylinder is attached to a shalt. (not shown). Zach conducting section is provided with a dried protective coating 5 of enamel or some other suitableinsulating material over those portions of its surfaces which the. molded insulating material eugages. The al'otective coating may be applied by dipping each section or b apply: mg the coat 11;: to the exposed surl'aces oi the assemble'd sections. The. coating prw vents the inslulating material which passes Specification of Letters Batent.

Patented Deo.'30, 1919.

I Application filed September 1o, 1917. Serial no. 190,508.

over the cylinder, under the infiuenceof heat and pressure, from coming into. contact with the conducting portions and thus prevents any flakes of copper from being. re-

moved b the scouring action. In this way,

the possi ility of short circuits occurring between the conducting sections is substan-' tially eliminated. 1

\Vhile I have shown my invention as applied to conductingisections of commutator cylinders, it will e understood by'those skilled in theart that it is not so limited, but may be applied to a conductor orother body which is subject to having molded insulating material pass over it, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the.

prior art or are specifically set forth in the appended claims.

I claim as my invention: l. A conducting member embedded in molded insulating material. and having its embedded portion-provided with aprotec-V emidueting member being provided with a.

' protective coating of enamel.

The method of molding composite bodies of insulating material with inserts of conducting material whichcomprises providing the inserts with a protective coating, embedding them in the insulating material and molding the body thus assembled.

(1. The method of molding composite bodies of an insulating material which will harden under tlaflapplication of heat amt pressure with inserts of conducting material which comprises providing the inserts with a protective. coating, emlmdding them in the nmterial and molding the body thus assembled by application of heat. aml pressure.

7. The. method of molding composite bodies of a. phenolic condensation product and metallic inserts which comprises providing the surface of the inserts with a protective coating of enamel, drying the coating, embedding the inserts in the phenolic condensation product and hardening the henolic qondensation product by the app ication of heat and pressure.

8. The method of forming a commutator in which commutator bars are embedded in an insulating material which hardens under the application of heatand pressure which comprises providing the surfaces of the barswith a protective coating, embedding the bars in the insulating material and sub- 

